Editing documents with paperless-ngx 2.0 fails

[cmusik]

Describe the bug
Since Paperless-ngx 2.0 editing documents does not work

To Reproduce

1. Open document
2. Change something
3. Save

Expected behavior
Changes are saved

Logs

In the edit request I get the message:

{"custom_fields":["Dieses Feld ist erforderlich."]}

In the app logs there is this stacktrace:

---BEGIN STACKTRACE---
#0      PaperlessDocumentsApiImpl.update (package:paperless_api/src/modules/documents_api/paperless_documents_api_impl.dart:85)
<asynchronous suspension>
#1      DocumentEditCubit.updateDocument (package:paperless_mobile/features/document_edit/cubit/document_edit_cubit.dart:35)
<asynchronous suspension>
#2      _DocumentEditPageState._onSubmit (package:paperless_mobile/features/document_edit/view/document_edit_page.dart:389)
<asynchronous suspension>

---END STACKTRACE---

Additional information
Paperless App Version: 3.1.3
Do you use Paperless NG as a backend: Yes

[cmusik]

sorry, wrong paperless app